But, besides creatures fully formed, the atmosphere contains innumerable germs of future life, such as the eggs of insects and the seeds of plants, the latter provided with light hairy or feathery appendages, by means of which they are wafted through the air during long autumnal wanderings. Even the fertilizing dust or pollen from the anthers of the male flowers, in species in which the sexes are separated, is carried over land and sea, by winds and by the agency of winged insects,[4] to the solitary female plant on other shores. Thus wherever the glance of the inquirer into Nature penetrates, he sees the continual dissemination of life, either fully formed or in the germ. If the aereal ocean in which we are submerged, and above the surface of which we cannot rise, be indispensable to the existence of organised beings, they also require a more substantial aliment, which they can find only at the bottom of this gaseous ocean. This bottom is of two kinds; the smaller portion consisting of dry land in immediate contact with the external atmosphere, and the larger portion consisting of water, which may perhaps have been formed thousands of years ago by electric agencies from gaseous substances, and which is now incessantly undergoing decomposition in the laboratories of Nature, in the clouds and in the pulsating vessels of animals and plants. Organic forms also descend deep below the surface of the earth, wherever rain or surface water can percolate either by natural cavities or by mines or other excavations made by man: the subterranean cryptogamic Flora was an object of my scientific research in the early part of my life. Thermal springs of very high temperature nourish small Hydropores, Confervæ, and Oscillatoria. At Bear Lake, near the Arctic Circle, Richardson saw the ground, which continues frozen throughout the summer at a depth of twenty inches, covered with flowering plants.